For the chimichurri sauce:
1 1/2 cups packed fresh parsley
1/4 cup packed fresh cilantro
1 cup olive oil
1/4 cup red wine vinegar
2 tablespoons dried oregano
1 1/2 tablespoons cumin
1 1/2 teaspoons salt
3 cloves garlic
3/4 teaspoon red pepper flakes
For the chicken and vegetables:
1 1/2 pounds boneless, skinless chicken breasts
1 pound new potatoes, quartered
1 pound asparagus, ends trimmed
2 tablespoons olive oil
1 teaspoon salt
1/2 teaspoon ground black pepper
1 teaspoon dried oregano
1 teaspoon cumin
In a food processor or blender, combine the parsley, cilantro, olive oil, vinegar, oregano, cumin, salt, garlic and pepper flakes. Puree for 2 to 3 minutes, or until very smooth.
Pour half of the chimichurri sauce into an 8-by-8-inch baking dish. Pour the remaining sauce into a bowl, cover and refrigerate.
Carefully slice each breast into long, thin slices about 1/2 inch thick. Place the chicken slices in the baking dish and turn to coat with chimichurri. Cover, set aside.
Meanwhile, heat the oven to 400 degrees. Line 2 rimmed baking sheets with foil.
In a large bowl, combine the potatoes and asparagus. In a small bowl, whisk together the olive oil, salt, pepper, oregano and cumin. Drizzle over the vegetables, then toss to coat.
Arrange the potatoes and asparagus in an even layer on the baking sheet, then place on the oven’s upper rack. Roast for 35 minutes. Remove the pan from the oven and set the oven to broil.
Arrange the chicken in a single layer on the second baking sheet. Discard any excess marinade. Place on the oven’s center rack and broil for 5 minutes, then turn the chicken and broil for another 5 minutes. Serve the chicken and vegetables with the reserved chimichurri sauce for dipping.